Aerosol provision systems such as e-cigarettes generally contain a reservoir of a source liquid containing a formulation, typically including nicotine, for which an aerosol is generated, e.g. through vaporization or other means. Thus an aerosol source for an aerosol provision system may comprise a heater coupled to a portion of the source liquid from the reservoir. When a user inhales on the device, the heater is activated to vaporize a small amount of the source liquid, which is thus converted to an aerosol for inhalation by the user. More particularly, such devices are usually provided with one or more air inlet holes located away from a mouthpiece of the system. When a user sucks on the mouthpiece, air is drawn in through the inlet holes and past the aerosol source. There is a flow path connecting between the aerosol source and an opening in the mouthpiece so that air drawn past the aerosol source continues along the flow path to the mouthpiece opening, carrying some of the aerosol from the aerosol source with it. The aerosol-carrying air exits the aerosol provision system through the mouthpiece opening for inhalation by the user.
A problem can arise in aerosol provision systems of the kind discussed above whereby a portion of the aerosol may deposit (condense) on an inner wall of the flow path connecting the aerosol source to the mouthpiece opening. This can lead to the build-up of droplets of the formulation from the source liquid forming on the wall of the flow path. These droplets may then become entrained in air flowing through the flow path and drawn into a user's mouth. This can detract from the user's experience, for example, because the droplets may be tasted. This problem may in some respects be referred to as mouth leakage.
Some issues relating to aerosol condensation in an inhaler have been previously considered in US 2011/0226236. In particular, US 2011/0226236 recognizes a desire to avoid frequent changes of mouthpiece resulting from condensate build-up. To address this issue, US 2011/0226236 proposes using an absorbent body in conjunction with a cooler to capture and store components of the aerosol that might otherwise condense in the mouthpiece. The approach of US 2011/0226236 has drawbacks in that it relies on a relatively complex two-stage solution that takes up space in the inhaler.
Accordingly there remains a need for aerosol provision systems which seek to ameliorate some of the issues discussed above relating to aerosol condensation.